FFMPEG is so goddamn cool, I was doing a mod for warcraft 3 where I restore the original Frozen Throne UI and one (especially useful before, Blizzard now restored the classic WEBM models so that part is now outdated but the blue buttons and other stuff are still relevant).

And virtually every method was failing in decoloring the "chains".webm video that Reforged has on the bottom corners (by default it has a very rusty feeling that fits reign of chaos more than the frozen throne)... but FFMPEG via commands did it perfectly fine, extremely easily by doing it frame by frame, actually incredible that this software is completely free.